The alert system of an aircraft or “Flight Warning System” (FWS) is a system at the core of the aircraft. It generally comprises a system for managing procedures and an alarms facility.
It indicates to the pilot the procedures to be followed for managing the airplane, be it in nominal mode or in degraded mode. Quantitatively, an FWS manages of the order of 5000 signals, 1000 alerts and 1000 procedures.
This alert system is connected to most of the airplane's electronic equipment, such as for example to the fuel management system, to the electrical or hydraulic system, to mention just a few.
The various electronic systems evolve in the course of the development of the airplane, be it in their interface or in the dynamic behaviors of the signals generated, so that the fine tuning of an FWS is done throughout the development cycle and up to the last flights preceding the certification flights.
Thus, the FWS alert system is, through its central position, modified and updated continually during the development of the airplane but essentially in the home straight just before certification.
Hence the design of an FWS may not leave room for inaccuracies and gaps. And an airplane rigger must ensure that all the alert requirements have been captured as a function of the feared events and of the operations of the airplane's various sub-systems.
The capture of the alert requirement is commonly carried out in a documentary manner solely by using documentary models which list predefined situations. Moreover, verification of the completeness of this requirement is done through a process of documentary review.
Thus, the expression of the alert requirement has to date been done in natural language and its accuracy remains interpretable. This may give rise to inaccuracies and technical incompatibilities.
The requirement thus exists for a solution which makes it possible to group the alert requirements together in a complete manner and makes it possible to circumvent errors of interpretation.